Upon joining the Yankees in 1997, he unsuccessfully petitioned his new club for Babe Ruth's number "3" (long retired) and later in the year was chastised for wearing one of the Babe's caps during a game. He often annoyed managers with a reluctance to get in shape and various off-the-field antics, including a broken finger suffered in a bar brawl before the 1998 season. Despite the injury, Wells didn't miss any action; in fact, he made history that May when he became only the second Yankee ever to throw a perfect game. In doing so, he followed fellow Point Loma High alumnus Larsen, who hurled his in Game Five of the 1956 World Series.
A starter for most of his minor-league career, Wells broke into the majors in 1987 with Toronto in 1987 as a middle reliever, joining a first-class bullpen that featured AL saves champ Tom Henke and workhorse Mark Eichhorn. By 1988, the portly portsider had found a niche as manager Jimy Williams' top middle reliever and left-handed specialist. He enjoyed a terrific season for the division champs in 1989, posting the lowest ERA of his career (2.40) with 78 strikeouts and only 28 walks in just over 86 innings.
The addition of veteran lefty Ken Dayley in 1990 allowed Blue Jays manager Cito Gaston to give Wells a shot at the rotation a month into the season. In 25 starts, Wells logged 165 innings and walked only 45 with an ERA of 3.14 -- good for second-best on the starting staff, and seventh-best in the league. In 1991, he went 15-10 while keeping his ERA below four for the third straight year. He still allowed 24 homers, the most of any pitcher on the Toronto staff.
Wells started the 1992 season in the Blue Jays rotation, but was the odd man out among a talented bunch of starters that included Jimmy Key, Todd Stottlemyre, Juan Guzman, and veteran Jack Morris, who was signed as a free-agent during the offseason. Moreover, former ace Dave Stieb was due to return to action after missing most of 1991 with a herniated disk in his back. By April 22, Stieb had returned and Wells was back in the bullpen.
At the end of the year Wells filed for free agency, announcing he would never pitch for Toronto again. Instead, he inked a deal with the Detroit Tigers just two days before Opening Day. He quickly established himself as the anchor of a less-than-stellar Detroit rotation, winning nine of his first ten decisions with a 2.38 ERA and finishing the season with the most strikeouts on the Tigers' staff.
A short stint on the DL that August was followed by arthroscopic surgery to remove bone chips in his left elbow at the start of the 1994 campaign. After returning from a rehab assignment on June 4, Wells threw five complete games and his first-ever major league shutout. In his last eight starts (a span of 61 2/3 innings) he walked just eight batters.
Despite establishing himself as the team's ace with a 10-3 start in 1995, Wells was traded to Cincinnati for three players in late July. He was a good addition for Davey Johnson's Reds, hurling three complete games down the stretch, but couldn't beat Atlanta in Game Three of the NLCS as the Braves swept the Reds to advance to the World Series. Victim of an acrimonious relationship with Cincinnati manager Davey Johnson, the 32-year-old Wells was traded to the Baltimore Orioles after the season for utility outfielder Curtis Goodwin and a minor-leaguer before the 1996 season, and worked a career-high 224 innings, walking only 51. Except for 1995 (in which he'd allowed 53 free passes), it was the most walks he'd ever allowed in a full season.
Wells joined the New York Yankees as a free agent in 1997. Only Andy Pettitte (18) had more wins than Wells, who went 16-10 as the Bronx Bombers finished second to the Orioles by two games in the AL East. The veteran lefty, always susceptible to the long ball, gave up 24 homers to lead the Yankee staff but ranked third in the AL in complete games (5) and shutouts (2). Wells emerged as the ace of the staff with a sterling season in 1998 (18-4, 3.49,) helping the Yankees win the most games in American League history.
Virtually untouchable at home throughout the season, Wells went 11-1 in the house that Ruth built and won New York fans' hearts by throwing a perfect game against the hapless Minnesota Twins on April 17, 1998. In front of a packed house (most lured by the promise of free Beanie Babies) Wells became only the second pitcher in history to throw a perfect game at Yankee Stadium. Until then, Wells had never allowed fewer than three hits in a game as a starter.
His secret? "I didn't take creatine," Wells revealed in an interview with Penthouse published the following year. "I drank beer, and I had a career year."
Reporting to spring training in February 1999, part of a three-player package that included infielder Homer Bush and reliever Graeme Lloyd for five-time Cy Young Award winner Roger Clemens. Shocked and dismayed at leaving New York, Wells hurled expletives at reporters and raised his middle finger for photographers while taking a physical at Toronto's spring training camp but insisted he held no bitterness towards his former team.